Debugger[CDB]: Correct minimum version in documentation.

Version 6.11 has a limitation in that it cannot handle
some symbol group entries of the form (class Foo*)(address),
leading to <Syntax error> values.

Task-number: QTCREATORBUG-4185

doc/qtcreator.qdoc

@@ -7266,7 +7266,7 @@
                \l{http://www.microsoft.com/whdc/devtools/debugging/installx86.Mspx}
                or
                \l{http://www.microsoft.com/whdc/devtools/debugging/install64bit.Mspx}
-               package (Version 6.11.1.404 for the 32-bit or the 64-bit version
+               package (Version 6.12 for the 32-bit or the 64-bit version
                of Qt Creator, respectively),
                which are freely available for download from the
                \l{http://msdn.microsoft.com/en-us/default.aspx}{Microsoft Developer Network}.